Chip package having die structures of different heights and method of forming same

Abstract

Structures and formation methods of a chip package are provided. The chip package includes a chip stack including a number of semiconductor dies. The chip package also includes a semiconductor chip, and the semiconductor chip is higher than the chip stack. The chip package further includes a package layer covering a top and sidewalls of the chip stack and sidewalls of the semiconductor chip.

What is claimed is: 
     
       1. A chip package, comprising:
 a chip stack including a plurality of semiconductor dies; 
 a semiconductor chip, wherein the semiconductor chip is higher than the chip stack; and 
 a package layer overfilling a gap between the chip stack and the semiconductor chip, the package layer covering a top and sidewalls of the chip stack and sidewalls of the semiconductor chip. 
 
     
     
       2. The chip package as claimed in  claim 1 , wherein a top surface of the semiconductor chip is not covered by the package layer. 
     
     
       3. The chip package as claimed in  claim 1 , further comprising a substrate, wherein the chip stack and the semiconductor chip are bonded on the substrate through conductive bonding structures. 
     
     
       4. The chip package as claimed in  claim 3 , wherein the substrate is a semiconductor substrate. 
     
     
       5. The chip package as claimed in  claim 4 , further comprising a conductive feature penetrating through the substrate and electrically connected to one of the conductive bonding structures. 
     
     
       6. The chip package as claimed in  claim 3 , wherein the package layer surrounds and is in direct contact with the conductive bonding structures. 
     
     
       7. The chip package as claimed in  claim 3 , further comprising an underfill layer surrounding and in direct contact with the conductive bonding structures, wherein the underfill layer is between the substrate and the package layer. 
     
     
       8. The chip package as claimed in  claim 7 , wherein the underfill layer is in direct contact with the package layer. 
     
     
       9. The chip package as claimed in  claim 1 , wherein the chip stack comprises a plurality of memory dies. 
     
     
       10. The chip package as claimed in  claim 1 , wherein a top surface of the package layer is substantially coplanar with a top surface of the semiconductor chip. 
     
     
       11. The chip package as claimed in  claim 1 , wherein the chip stack comprises a molding compound layer surrounding the plurality of semiconductor dies. 
     
     
       12. A chip package, comprising:
 a first semiconductor chip; 
 a second semiconductor chip; and 
 a molding compound layer surrounding the first semiconductor chip and the second semiconductor chip, wherein the molding compound layer covers a top surface of the first semiconductor chip, and a top surface of the molding compound layer is substantially coplanar with a top surface of the second semiconductor chip. 
 
     
     
       13. The chip package as claimed in  claim 12 , wherein the second semiconductor chip is higher than the first semiconductor chip. 
     
     
       14. The chip package as claimed in  claim 12 , further comprising a substrate, wherein the first semiconductor chip and the second semiconductor chip are bonded on the substrate through conductive bonding structures. 
     
     
       15. The chip package as claimed in  claim 14 , further comprising a conductive feature penetrating through the substrate and electrically connected to one of the conductive bonding structures. 
     
     
       16. The chip package as claimed in  claim 14 , wherein the molding compound layer surrounds and is in direct contact with the conductive bonding structures. 
     
     
       17. A method for forming a chip package, comprising:
 bonding a first semiconductor chip and a second semiconductor chip over a substrate; 
 forming a package layer over the substrate to encapsulate the first semiconductor chip and the second semiconductor chip; and 
 planarizing the package layer so that a top surface of the second semiconductor chip is exposed, and a top surface of the first semiconductor chip is covered by the package layer. 
 
     
     
       18. The method for forming a chip package as claimed in  claim 17 , wherein the first semiconductor chip is not ground during the planarization process. 
     
     
       19. The method for forming a chip package as claimed in  claim 17 , wherein the first semiconductor chip and the second semiconductor chip are bonded onto the substrate through a plurality of conductive bonding structures. 
     
     
       20. The method for forming a chip package as claimed in  claim 19 , further comprising forming an underfill layer to surround the conductive bonding structures before the formation of the package layer.